1. Field of the Invention
The present invention relates to a petroleum well for producing petroleum products. In one aspect, the present invention relates to systems and methods for monitoring and/or improving fluid flow during petroleum production by controllably injecting chemicals into at least one fluid flow stream with at least one electrically controllable downhole chemical injection system of a petroleum well.
2. Description of Related Art
The controlled injection of materials into petroleum wells (i.e., oil and gas wells) is an established practice frequently used to increase recovery, or to analyze production conditions.
It is useful to distinguish between types of injection, depending on the quantities of materials that will be injected. Large volumes of injected materials are injected into formations to displace formation fluids towards producing wells. The most common example is water flooding.
In a less extreme case, materials are introduced downhole into a well to effect treatment within the well. Examples of these treatments include: (1) foaming agents to improve the efficiency of artificial lift; (2) paraffin solvents to prevent deposition of solids onto the tubing; and (3) surfactants to improve the flow characteristics of produced fluids. These types of treatment entail modification of the well fluids themselves. Smaller quantities are needed, yet these types of injection are typically supplied by additional tubing routed downhole from the surface.
Still other applications require even smaller quantities of materials to be injected, such as: (1) corrosion inhibitors to prevent or reduce corrosion of well equipment; (2) scale preventers to prevent or reduce scaling of well equipment; and (3) tracer chemicals to monitor the flow characteristics of various well sections. In these cases the quantities required are small enough that the materials may be supplied from a downhole reservoir, avoiding the need to run supply tubing downhole from the surface. However, successful application of such techniques requires controlled injection.
The controlled injection of materials such as water, foaming agents, paraffin solvents, surfactants, corrosion inhibitors, scale preventers, and tracer chemicals to monitor flow characteristics are documented in U.S. Pat. Nos. 4,681,164, 5,246,860, and 4, 068,717.
All references cited herein are incorporated by reference to the maximum extent allowable by law. To the extent a reference may not be fully incorporated herein, it is incorporated by reference for background purposes, and indicative of the knowledge of one of ordinary skill in the art.